[TowerTalk] antenna impedence and ground impedence??

[Tom Rauch]

Jim,

I'm not saying they don't exist, but  I have not yet found a coil modeling
program that agrees with direct measurements of large RF inductors. Is there
a link to that free program?

One program touted as being verified was actually "verified" with a 30 or
more year old instrument that wouldn't even work at HF!!! And it was for HF
inductors.

A good HF inductor modeling program would be nice to have!

In an offline exchange Dan (the person with the questions) stated the ESR of
his 2000 ohm reactance coil calculated or modeled to be 1.5 ohms. If you see
a Q that is much over 800 for large inductors and 300 for miniductor or
doesn't change with frequency, it is likely wrong.

> Here is an area where there ARE very accurate modeling programs available
> (sub percent accuracies, given mechanical dimensions and material data).
> INCA is one (and free, to boot).  The switching power supply business has
> fostered a lot of research into good analytical or numerical methods for
> measuring such things.

73 Tom